You ever heard a 2.4 with street race? Don't even think it is available for the 2.4 but I could be wrong.
I have "blown" out the baffles on the driver's side of my GXP exhaust (don't ask)... It is VERY RICEY!!! Defintiely Uncle Ben's. The 2.4L with a GXP exhaust sounds VERY aggressive. With a SOLO Cat, even better. Without a muffler... HORRIBLE!!! I know, I live it everyday.
So I agree with everyone. Free GXP exhoust is the way to go. If you are definitely going to buy a system, Go all the way, Go SOLO SQR2 with Norm's Facia.